| // Copyright 2014 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| import 'package:flutter/widgets.dart'; |
| import 'package:flutter_test/flutter_test.dart'; |
| |
| void main() { |
| testWidgets('Sliver with keep alive without key - should dispose after reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| const WidgetTest0(text: 'child 0', keepAlive: true), |
| const WidgetTest1(text: 'child 1', keepAlive: true), |
| const WidgetTest2(text: 'child 2', keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsNothing); |
| |
| expect(state0.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('Sliver without keep alive without key - should dispose after reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| const WidgetTest0(text: 'child 0'), |
| const WidgetTest1(text: 'child 1'), |
| const WidgetTest2(text: 'child 2'), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsNothing); |
| |
| expect(state0.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('Sliver without keep alive with key - should dispose after reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: GlobalKey()), |
| WidgetTest1(text: 'child 1', key: GlobalKey()), |
| WidgetTest2(text: 'child 2', key: GlobalKey()), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsNothing); |
| |
| expect(state0.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('Sliver with keep alive with key - should not dispose after reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: GlobalKey(), keepAlive: true), |
| WidgetTest1(text: 'child 1', key: GlobalKey(), keepAlive: true), |
| WidgetTest2(text: 'child 2', key: GlobalKey(), keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| expect(state0.hasBeenDisposed, false); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('Sliver with keep alive with Unique key - should not dispose after reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: UniqueKey(), keepAlive: true), |
| WidgetTest1(text: 'child 1', key: UniqueKey(), keepAlive: true), |
| WidgetTest2(text: 'child 2', key: UniqueKey(), keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| expect(state0.hasBeenDisposed, false); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('Sliver with keep alive with Value key - should not dispose after reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| const WidgetTest0(text: 'child 0', key: ValueKey<int>(0), keepAlive: true), |
| const WidgetTest1(text: 'child 1', key: ValueKey<int>(1), keepAlive: true), |
| const WidgetTest2(text: 'child 2', key: ValueKey<int>(2), keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| expect(state0.hasBeenDisposed, false); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('Sliver complex case 1', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: GlobalKey(), keepAlive: true), |
| WidgetTest1(text: 'child 1', key: GlobalKey(), keepAlive: true), |
| const WidgetTest2(text: 'child 2', keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest1State state1 = tester.state(find.byType(WidgetTest1)); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 1, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| expect(state0.hasBeenDisposed, false); |
| expect(state1.hasBeenDisposed, false); |
| // Child 2 does not have a key. |
| expect(state2.hasBeenDisposed, true); |
| }); |
| |
| testWidgets('Sliver complex case 2', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: GlobalKey(), keepAlive: true), |
| WidgetTest1(text: 'child 1', key: UniqueKey()), |
| const WidgetTest2(text: 'child 2', keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| final _WidgetTest1State state1 = tester.state(find.byType(WidgetTest1)); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 1, 2); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget(SwitchingChildListTest(children: childList)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| expect(state0.hasBeenDisposed, false); |
| expect(state1.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, true); |
| }); |
| |
| testWidgets('Sliver with SliverChildBuilderDelegate', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: UniqueKey(), keepAlive: true), |
| WidgetTest1(text: 'child 1', key: GlobalKey()), |
| const WidgetTest2(text: 'child 2', keepAlive: true), |
| ]; |
| await tester.pumpWidget(SwitchingChildBuilderTest(children: childList)); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget(SwitchingChildBuilderTest(children: childList)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 2'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget(SwitchingChildBuilderTest(children: childList)); |
| final _WidgetTest1State state1 = tester.state(find.byType(WidgetTest1)); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 1, 2); |
| await tester.pumpWidget(SwitchingChildBuilderTest(children: childList)); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 0', skipOffstage: false), findsOneWidget); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget(SwitchingChildBuilderTest(children: childList)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1', skipOffstage: false), findsNothing); |
| expect(find.text('child 2', skipOffstage: false), findsNothing); |
| |
| expect(state0.hasBeenDisposed, false); |
| expect(state1.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, true); |
| }); |
| |
| testWidgets('SliverFillViewport should not dispose widget with key during in screen reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: UniqueKey(), keepAlive: true), |
| WidgetTest1(text: 'child 1', key: UniqueKey()), |
| const WidgetTest2(text: 'child 2', keepAlive: true), |
| ]; |
| await tester.pumpWidget( |
| SwitchingChildListTest(viewportFraction: 0.1, children: childList), |
| ); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| final _WidgetTest1State state1 = tester.state(find.byType(WidgetTest1)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2'), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget( |
| SwitchingChildListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget( |
| SwitchingChildListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 1, 2); |
| await tester.pumpWidget( |
| SwitchingChildListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget( |
| SwitchingChildListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| expect(state0.hasBeenDisposed, false); |
| expect(state1.hasBeenDisposed, false); |
| expect(state2.hasBeenDisposed, true); |
| }); |
| |
| testWidgets('SliverList should not dispose widget with key during in screen reordering', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: UniqueKey(), keepAlive: true), |
| const WidgetTest1(text: 'child 1', keepAlive: true), |
| WidgetTest2(text: 'child 2', key: UniqueKey()), |
| ]; |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| final _WidgetTest1State state1 = tester.state(find.byType(WidgetTest1)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2'), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 1, 2); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 1, 2); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 0, 2); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| expect(state0.hasBeenDisposed, false); |
| expect(state1.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, false); |
| }); |
| |
| testWidgets('SliverList remove child from child list', (WidgetTester tester) async { |
| List<Widget> childList= <Widget>[ |
| WidgetTest0(text: 'child 0', key: UniqueKey(), keepAlive: true), |
| const WidgetTest1(text: 'child 1', keepAlive: true), |
| WidgetTest2(text: 'child 2', key: UniqueKey()), |
| ]; |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| final _WidgetTest0State state0 = tester.state(find.byType(WidgetTest0)); |
| final _WidgetTest1State state1 = tester.state(find.byType(WidgetTest1)); |
| final _WidgetTest2State state2 = tester.state(find.byType(WidgetTest2)); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2'), findsOneWidget); |
| |
| childList = createSwitchedChildList(childList, 0, 1); |
| childList.removeAt(2); |
| await tester.pumpWidget( |
| SwitchingSliverListTest(viewportFraction: 0.1, children: childList), |
| ); |
| expect(find.text('child 0'), findsOneWidget); |
| expect(find.text('child 1'), findsOneWidget); |
| expect(find.text('child 2'), findsNothing); |
| expect(state0.hasBeenDisposed, false); |
| expect(state1.hasBeenDisposed, true); |
| expect(state2.hasBeenDisposed, true); |
| }); |
| } |
| |
| List<Widget> createSwitchedChildList(List<Widget> childList, int i, int j) { |
| final Widget w = childList[i]; |
| childList[i] = childList[j]; |
| childList[j] = w; |
| return List<Widget>.from(childList); |
| } |
| |
| class SwitchingChildBuilderTest extends StatefulWidget { |
| const SwitchingChildBuilderTest({ |
| required this.children, |
| Key? key, |
| }) : super(key: key); |
| |
| final List<Widget> children; |
| |
| @override |
| State<SwitchingChildBuilderTest> createState() => _SwitchingChildBuilderTest(); |
| } |
| |
| class _SwitchingChildBuilderTest extends State<SwitchingChildBuilderTest> { |
| late List<Widget> children; |
| late Map<Key, int> _mapKeyToIndex; |
| |
| @override |
| void initState() { |
| super.initState(); |
| children = widget.children; |
| _mapKeyToIndex = <Key, int>{}; |
| for (int index = 0; index < children.length; index += 1) { |
| final Key? key = children[index].key; |
| if (key != null) { |
| _mapKeyToIndex[key] = index; |
| } |
| } |
| } |
| |
| @override |
| void didUpdateWidget(SwitchingChildBuilderTest oldWidget) { |
| super.didUpdateWidget(oldWidget); |
| if (oldWidget.children != widget.children) { |
| children = widget.children; |
| _mapKeyToIndex = <Key, int>{}; |
| for (int index = 0; index < children.length; index += 1) { |
| final Key? key = children[index].key; |
| if (key != null) { |
| _mapKeyToIndex[key] = index; |
| } |
| } |
| } |
| } |
| |
| @override |
| Widget build(BuildContext context) { |
| return Directionality( |
| textDirection: TextDirection.ltr, |
| child: Center( |
| child: SizedBox( |
| height: 100, |
| child: CustomScrollView( |
| cacheExtent: 0, |
| slivers: <Widget>[ |
| SliverFillViewport( |
| delegate: SliverChildBuilderDelegate( |
| (BuildContext context, int index) { |
| return children[index]; |
| }, |
| childCount: children.length, |
| findChildIndexCallback: (Key key) => _mapKeyToIndex[key] ?? -1, |
| ), |
| ), |
| ], |
| ), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| class SwitchingChildListTest extends StatefulWidget { |
| const SwitchingChildListTest({ |
| required this.children, |
| this.viewportFraction = 1.0, |
| Key? key, |
| }) : super(key: key); |
| |
| final List<Widget> children; |
| final double viewportFraction; |
| |
| @override |
| State<SwitchingChildListTest> createState() => _SwitchingChildListTest(); |
| } |
| |
| class _SwitchingChildListTest extends State<SwitchingChildListTest> { |
| @override |
| Widget build(BuildContext context) { |
| return Directionality( |
| textDirection: TextDirection.ltr, |
| child: Center( |
| child: SizedBox( |
| height: 100, |
| child: CustomScrollView( |
| cacheExtent: 0, |
| slivers: <Widget>[ |
| SliverFillViewport( |
| viewportFraction: widget.viewportFraction, |
| delegate: SliverChildListDelegate(widget.children), |
| ), |
| ], |
| ), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| class SwitchingSliverListTest extends StatefulWidget { |
| const SwitchingSliverListTest({ |
| required this.children, |
| this.viewportFraction = 1.0, |
| Key? key, |
| }) : super(key: key); |
| |
| final List<Widget> children; |
| final double viewportFraction; |
| |
| @override |
| State<SwitchingSliverListTest> createState() => _SwitchingSliverListTest(); |
| } |
| |
| class _SwitchingSliverListTest extends State<SwitchingSliverListTest> { |
| @override |
| Widget build(BuildContext context) { |
| return Directionality( |
| textDirection: TextDirection.ltr, |
| child: Center( |
| child: SizedBox( |
| height: 100, |
| child: CustomScrollView( |
| cacheExtent: 0, |
| slivers: <Widget>[ |
| SliverList( |
| delegate: SliverChildListDelegate(widget.children), |
| ), |
| ], |
| ), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| class WidgetTest0 extends StatefulWidget { |
| const WidgetTest0({ |
| required this.text, |
| this.keepAlive = false, |
| Key? key, |
| }) : super(key: key); |
| |
| final String text; |
| final bool keepAlive; |
| |
| @override |
| State<WidgetTest0> createState() => _WidgetTest0State(); |
| } |
| |
| class _WidgetTest0State extends State<WidgetTest0> with AutomaticKeepAliveClientMixin { |
| bool hasBeenDisposed = false; |
| |
| @override |
| Widget build(BuildContext context) { |
| super.build(context); |
| return Text(widget.text); |
| } |
| |
| @override |
| void dispose() { |
| hasBeenDisposed = true; |
| super.dispose(); |
| } |
| |
| @override |
| bool get wantKeepAlive => widget.keepAlive; |
| } |
| |
| class WidgetTest1 extends StatefulWidget { |
| const WidgetTest1({ |
| required this.text, |
| this.keepAlive = false, |
| Key? key, |
| }) : super(key: key); |
| |
| final String text; |
| final bool keepAlive; |
| |
| @override |
| State<WidgetTest1> createState() => _WidgetTest1State(); |
| } |
| |
| class _WidgetTest1State extends State<WidgetTest1> with AutomaticKeepAliveClientMixin { |
| bool hasBeenDisposed = false; |
| |
| @override |
| Widget build(BuildContext context) { |
| super.build(context); |
| return Text(widget.text); |
| } |
| |
| @override |
| void dispose() { |
| hasBeenDisposed = true; |
| super.dispose(); |
| } |
| |
| @override |
| bool get wantKeepAlive => widget.keepAlive; |
| } |
| |
| class WidgetTest2 extends StatefulWidget { |
| const WidgetTest2({ |
| required this.text, |
| this.keepAlive = false, |
| Key? key, |
| }) : super(key: key); |
| |
| final String text; |
| final bool keepAlive; |
| |
| @override |
| State<WidgetTest2> createState() => _WidgetTest2State(); |
| } |
| |
| class _WidgetTest2State extends State<WidgetTest2> with AutomaticKeepAliveClientMixin { |
| bool hasBeenDisposed = false; |
| |
| @override |
| Widget build(BuildContext context) { |
| super.build(context); |
| return Text(widget.text); |
| } |
| |
| @override |
| void dispose() { |
| hasBeenDisposed = true; |
| super.dispose(); |
| } |
| |
| @override |
| bool get wantKeepAlive => widget.keepAlive; |
| } |